The present invention relates to the field of plasma engineering, particularly to electrodes for low temperature AC (alternating current and voltage) plasma generators, and more particularly the materials for fabricating such electrodes which have heat conduction, electric conductance, structural strength and electron emitting characteristics.
In the field of plasma engineering, substantial effort has been directed to manufacturing of electrodes for low temperature plasma generators providing emission of electrons and stable arc burning, i.e., AC plasma electrodes. Such electrodes have typically been made from copper and chromium carbide, although other materials and methods for production have been proposed.
In general, materials for electrodes (not AC plasma electrodes) containing barium and/or barium oxide as a component emitting electrons was proposed in U.S. Pat. No. 5,126,622 issued Jun. 30, 1992 to J. Jeong et al. Emitter of electrons is enclosed in porous metal material which has a lot of diffusion cavities. European Patent Application No. 0537495 published Apr. 21, 1993 proposes to mix dry metal powders with high melting point, high heat resistance and substances emitting electrons for manufacturing electrodes. The mixture is compacted in the sealed reaction vessel and is subjected to hot isostalic compacting to obtain a semifinished item which is processed on the machine-tool to receive the electrode of the designed shape. Barium aluminate is the substance emitting electrons.
U.S. Pat. No. 5,128,584 issued Jul. 7, 1992 to J. Choi proposes an impregnated dispersion electrode containing a porous metal matrix impregnated with the material, emitting electrons on the basis of scandium or scandium tungstate. By this means the availability of an emitting additive and metal matrix, providing current supply and fixating emitting addition, are common for all mentioned above patents. The present invention is based on the same principle but other combinations of components are used as a base and an emitter.